That doesn't actually affect anything we ship or might _want_ to ship,

though, does it?

Probably not.

It mainly affects people who want to do large-scale number crunching (32
bit arrays have a similar limit which also goes away on 64 bit). For me
it was loading large XML documents into memory.

s/port/debug/
Most of the work is done -- it builds, the native compiler works, and
the test cases I tried it with all work.... except for freetennis, which
segfaults after bringing up the first window. I kind of got stuck there
because it was all static libraries and the debug information was
missing; I need to build it all manually to poke at it.